1. Field of Use
This invention relates generally to a control system for a variable capacity gas compressor. In particular it relates to a control system for operating the adjustable compressor slide valve in response to signals representative of compressor capacity and a variable system condition, such as gas pressure or temperature at the compressor inlet, outlet, or elsewhere in the system, to regulate compressor capacity and thereby maintain the variable system condition within a predetermined range.
2. Description of the Prior Art
My U.S. Pat. No. 3,924,972 issued Dec. 9, 1975 and assigned to the same assignee as the present application is entitled "Control Means For A Variable Capacity Rotary Screw Compressor" and discloses a control system wherein the slide valve is adjusted to regulate compressor capacity and maintain a system condition within a predetermined range. The compressor disclosed in that patent employed a slide valve having a stem which extended outwardly from within the compressor housing and the control system employed electromechanical means connected to the stem for ascertaining slide valve position and for deriving and providing an electrical signal representative of compressor capacity.